Method for determining transmit power in coverage enhancement scenario and device

• US 10,560,907 B2
• Filed: 11/03/2017
• Issued: 02/11/2020
• Est. Priority Date: 01/28/2014
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Zhang, Xiangdong, Xia, Jinhuan
• Primary Examiner(s): Lee, John J
• Application Number:
  US15/803,587
• Publication Number:
  US 20180063800A1
• Time in Patent Office: 830 Days
• Field of Search: 455522, 455 69, 455 68, 455 6711, 455509, 4554521, 4554221, 455446, 4554561, 4554563
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04W 16/00 Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/226 using past references to control power, e.g. look-up-table
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 72/51 based on terminal or device properties

Abstract

A method for determining a transmit power in a coverage enhancement scenario and a device resolve a problem that the prior art lacks a solution to determining a transmit power of a preamble sequence in a random access process in the coverage enhancement scenario. The method includes: obtaining, by a terminal, configuration information that is used to determine a transmit power used for transmitting a signal at each coverage enhancement level; and determining, by the terminal according to the obtained configuration information, a transmit power used for transmitting the signal at a coverage enhancement level currently used by the terminal, so as to determine the transmit power used for transmitting the signal in the coverage enhancement scenario.

Claims

1. An apparatus, comprising:

a memory to store program code;

a processor in communication with the memory; and

wherein the program code, when executed by the processor, causes the apparatus to;

obtain configuration information for determining a transmit power used for transmitting a signal at each coverage enhancement level,

determine, according to the configuration information, a transmit power used for transmitting the signal at a coverage enhancement level currently used by the apparatus,

when the configuration information comprises a maximum quantity of signal transmitting attempts corresponding to each coverage enhancement level, determine, from the configuration information, a maximum quantity of signal transmitting attempts at the coverage enhancement level currently used by the apparatus, and

transmit the signal using the determined transmit power.

2. The apparatus according to claim 1, wherein the configuration information comprises at least one of the following information:

a power compensation value corresponding to each coverage enhancement level;

a quantity of repetition times required for the signal to be transmitted at each coverage enhancement level;

a total of maximum quantities of signal transmitting attempts at all the coverage enhancement levels;

a power ramping step in each signal transmitting attempt corresponding to each coverage enhancement level;

or

a total of power ramping steps after the signal is transmitted repeatedly for N times in each attempt corresponding to each coverage enhancement level.

3. The apparatus according to claim 2, wherein to determine, according to the configuration information, the transmit power used for transmitting the signal at a coverage enhancement level currently used by the apparatus, the program code, when executed by the processor, causes the apparatus to:

determine, according to a correspondence between a quantity of repetition times and a power compensation value, a power compensation value corresponding to the quantity of repetition times required for the signal to be transmitted at the coverage enhancement level currently used by the apparatus; and

determine, according to the determined power compensation value, the transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus.

4. The apparatus according to claim 3, wherein the transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus meets the following formula:

P=min{P_MAX,PREAMBLE_RECEIVED_TARGET_POWER_CI+PL},

wherein P is the transmit power of transmitting the signal by the apparatus, P_MAX is a maximum transmit power of the apparatus, PREAMBLE_RECEIVED_TARGET_POWER_CI is a target received power determined according to the power compensation value corresponding to the coverage enhancement level currently used by the apparatus, and PL is a path loss.

5. The apparatus according to claim 4, wherein the target received power meets the following formula:

PREAMBLE_RECEIVED_TARGET_POWER_CI=preambleInitialReceivedTargetPower+DELTA_PREAMBLE_G_Ri+(PREAMBLE_TRANSMISSION_COUNTER_CI−

1)*powerRampingStep_CI,

wherein G_Ri is the power compensation value, preambleInitialReceivedTargetPower is an initial target received power, DELTA_PREAMBLE is an offset corresponding to a format of the signal, PREAMBLE_TRANSMISSION_COUNTER_CI is a quantity of signal transmitting attempts at the coverage enhancement level currently used by the apparatus, and powerRampingStep_CI is a power ramping step in each signal transmitting attempt at the coverage enhancement level currently used by the apparatus.

6. The apparatus according to claim 5, wherein DELTA_PREAMBLE is 0.

7. The apparatus according to claim 1, wherein the signal comprises at least one of data or a random access preamble sequence.

8. The apparatus according to claim 7, wherein, the signal comprises a random access preamble sequence, and when a random access process is not successful after power ramping is performed according to a maximum quantity of attempts corresponding to the coverage enhancement level currently used by the apparatus, the program code, when executed by the processor, causes the apparatus to switch to a higher coverage enhancement level to continue attempting.

9. An apparatus, comprising:

a memory to store program code;

a processor in communication with the memory; and

wherein the program code, when executed by the processor, causes the apparatus to;

obtain configuration information for determining a transmit power used for transmitting a signal at each coverage enhancement level, wherein the configuration information comprises a quantity of repetition times required for the signal to be transmitted at a coverage enhancement level currently used by the apparatus,

determine, according to the quantity of repetition times, a transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus, and

transmit the signal using the determined transmit power.

10. The apparatus according to claim 9, wherein the program code, when executed by the processor, further causes the apparatus to:

determine, according to a correspondence between the quantity of repetition times and a power compensation value, a power compensation value corresponding to the quantity of repetition times required for the signal to be transmitted at the coverage enhancement level currently used by the apparatus; and

determine, according to the determined power compensation value, the transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus.

11. The apparatus according to claim 10, wherein the transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus meets the following formula:

P=min{P_MAX,PREAMBLE_RECEIVED_TARGET_POWER_CI+PL},

wherein P is the transmit power of transmitting the signal by the apparatus, P_MAX is a maximum transmit power of the apparatus, PREAMBLE_RECEIVED_TARGET_POWER_CI is a target received power determined according to the power compensation value corresponding to the coverage enhancement level currently used by the apparatus, and PL is a path loss.

12. The apparatus according to claim 11, wherein the target received power meets the following formula:

PREAMBLE_RECEIVED_TARGET_POWER_CI=preambleInitialReceivedTargetPower+DELTA_PREAMBLE_G_Ri+(PREAMBLE_TRANSMISSION_COUNTER_CI−

1)*powerRampingStep_CI,

wherein G_Ri is the power compensation value preambleInitialReceivedTargetPower is an, initial target received power, DELTA_PREAMBLE is an offset corresponding to a format of the signal, PREAMBLE_TRANSMISSION_COUNTER_CI is a quantity of signal transmitting attempts at the coverage enhancement level currently used by the apparatus, and powerRampingStep_CI is a power ramping step in each signal transmitting attempt at the coverage enhancement level currently used by the apparatus.

13. The apparatus according to claim 12, wherein DELTA_PREAMBLE is 0.

14. The apparatus according to claim 9, wherein the configuration information comprises at least one of the following information:

a power compensation value corresponding to each coverage enhancement level;

a quantity of repetition times required for the signal to be transmitted at each coverage enhancement level;

a maximum quantity of signal transmitting attempts corresponding to each coverage enhancement level;

a total of maximum quantities of signal transmitting attempts at all the coverage enhancement levels;

a power ramping step in each signal transmitting attempt corresponding to each coverage enhancement level;

or

a total of power ramping steps after the signal is transmitted repeatedly for N times in each attempt corresponding to each coverage enhancement level.

15. The apparatus according to claim 9, wherein the signal comprises at least one of data or a random access preamble sequence.

16. The apparatus according to claim 15, wherein the signal comprises a random access preamble sequence, and when a random access process is not successful after power ramping is performed according to a maximum quantity of attempts corresponding to the coverage enhancement level currently used by the apparatus, the program code, when executed by the processor, causes the apparatus to switch to a higher coverage enhancement level to continue attempting.

17. A method, comprising:

obtaining, by an apparatus, configuration information, wherein the configuration information comprises a quantity of repetition times required for a signal to be transmitted at a coverage enhancement level currently used by the apparatus;

determining, by the apparatus according to the quantity of repetition times required for the signal to be transmitted at a coverage enhancement level currently used by the apparatus, a transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus; and

transmitting, by the apparatus, the signal using the determined transmit power.

18. The method according to claim 17, wherein determining, by the apparatus according to the quantity of repetition times required for the signal to be transmitted at a coverage enhancement level currently used by the apparatus, a transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus comprises:

determining, by the apparatus according to a correspondence between the quantity of repetition times and a power compensation value, a power compensation value corresponding to the quantity of repetition times required for the signal to be transmitted at the coverage enhancement level currently used by the apparatus; and

determining, by the apparatus according to the determined power compensation value, the transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus.

19. The method according to claim 18, wherein the transmit power used for transmitting the signal at the coverage enhancement level currently used by the apparatus meets the following formula:

P=min{P_MAX,PREAMBLE_RECEIVED_TARGET_POWER_CI+PL}

wherein P is the transmit power of transmitting the signal by the apparatus, P_MAX is a maximum transmit power of the apparatus, PREAMBLE_RECEIVED_TARGET_POWER_CI is a target received power determined according to the power compensation value corresponding to the coverage enhancement level currently used by the apparatus, and PL is a path loss.

20. The method according to claim 19, wherein the target received power meets the following formula:

PREAMBLE_RECEIVED_TARGET_POWER_CI=preambleInitialReceivedTargetPower+DELTA_PREAMBLE_G_Ri+(PREAMBLE_TRANSMISSION_COUNTER_CI−

1)*powerRampingStep_CI,

wherein G_Ri is the power compensation value, preambleInitialReceivedTargetPower is an initial target received power, DELTA_PREAMBLE is an offset corresponding to a format of the signal, PREAMBLE_TRANSMISSION_COUNTER_CI is a quantity of signal transmitting attempts at the coverage enhancement level currently used by the apparatus, and powerRampingStep_CI is a power ramping step in each signal transmitting attempt at the coverage enhancement level currently used by the apparatus.

21. The method according to claim 20, wherein DELTA_PREAMBLE is 0.

22. The method according to claim 17, wherein the configuration information comprises at least one of the following information:

a power compensation value corresponding to each coverage enhancement level;

a quantity of repetition times required for the signal to be transmitted at each coverage enhancement level;

a maximum quantity of signal transmitting attempts corresponding each coverage enhancement level;

a total of maximum quantities of signal transmitting attempts at all the coverage enhancement levels;

a power ramping step in each signal transmitting attempt corresponding to each coverage enhancement level;

or

a total of power ramping steps after the signal is transmitted repeatedly for N times in each attempt corresponding to each coverage enhancement level.

23. The method according to claim 17, wherein the signal comprises at least one of data or a random access preamble sequence.

24. The method according to claim 23, wherein the signal comprises a random access preamble sequence, and when a random access process is not successful after power ramping is performed according to a maximum quantity of attempts corresponding to the coverage enhancement level currently used by the apparatus, switching to a higher coverage enhancement level to continue attempting.